* packet encryption, packet authentication, and
* packet compression.
*
- * Copyright (C) 2002-2021 OpenVPN Inc <sales@openvpn.net>
+ * Copyright (C) 2002-2024 OpenVPN Inc <sales@openvpn.net>
* Copyright (C) 2010-2021 Fox Crypto B.V. <openvpn@foxcrypto.com>
*
* This program is free software; you can redistribute it and/or modify
* HMAC at all.
* - \b Ciphertext \b IV. The IV size depends on the \c \-\-cipher option.
* - \b Packet \b ID, a 32-bit incrementing packet counter that provides replay
- * protection (if not disabled by \c \-\-no-replay).
+ * protection.
* - \b Timestamp, a 32-bit timestamp of the current time.
* - \b Payload, the plain text network packet to be encrypted (unless
* encryption is disabled by using \c \-\-cipher \c none). The payload might
* both sending and receiving
* directions. */
struct packet_id packet_id; /**< Current packet ID state for both
- * sending and receiving directions. */
+ * sending and receiving directions.
+ *
+ * This contains the packet id that is
+ * used for replay protection.
+ *
+ * The packet id also used as the IV
+ * for AEAD/OFB/CFG ciphers.
+ * */
struct packet_id_persist *pid_persist;
/**< Persistent packet ID state for
* keeping state between successive
/**< Bit-flag indicating that data channel key derivation
* is done using TLS keying material export [RFC5705]
*/
+#define CO_RESEND_WKC (1<<4)
+ /**< Bit-flag indicating that the client is expected to
+ * resend the wrapped client key with the 2nd packet (packet-id 1)
+ * like with the HARD_RESET_CLIENT_V3 packet */
+#define CO_FORCE_TLSCRYPTV2_COOKIE (1<<5)
+ /**< Bit-flag indicating that we do not allow clients that do
+ * not support resending the wrapped client key (WKc) with the
+ * third packet of the three-way handshake */
+#define CO_USE_CC_EXIT_NOTIFY (1<<6)
+ /**< Bit-flag indicating that explicit exit notifies should be
+ * sent via the control channel instead of using an OCC message
+ */
+#define CO_USE_DYNAMIC_TLS_CRYPT (1<<7)
+ /**< Bit-flag indicating that renegotiations are using tls-crypt
+ * with a TLS-EKM derived key.
+ */
+
unsigned int flags; /**< Bit-flags determining behavior of
* security operation functions. */
};
*/
int write_key_file(const int nkeys, const char *filename);
-void generate_key_random(struct key *key, const struct key_type *kt);
-
-void check_replay_consistency(const struct key_type *kt, bool packet_id);
-
bool check_key(struct key *key, const struct key_type *kt);
bool write_key(const struct key *key, const struct key_type *kt,
struct gc_arena *gc);
-/** Calculate crypto overhead and adjust frame to account for that */
-void crypto_adjust_frame_parameters(struct frame *frame,
- const struct key_type *kt,
- bool packet_id,
- bool packet_id_long_form);
+/** Calculate the maximum overhead that our encryption has
+ * on a packet. This does not include needed additional buffer size
+ *
+ * This does NOT include the padding and rounding of CBC size
+ * as the users (mssfix/fragment) of this function need to adjust for
+ * this and add it themselves.
+ *
+ * @param kt Struct with the crypto algorithm to use
+ * @param packet_id_size Size of the packet id
+ * @param occ if true calculates the overhead for crypto in the same
+ * incorrect way as all previous OpenVPN versions did, to
+ * end up with identical numbers for OCC compatibility
+ */
+unsigned int
+calculate_crypto_overhead(const struct key_type *kt,
+ unsigned int pkt_id_size,
+ bool occ);
/** Return the worst-case OpenVPN crypto overhead (in bytes) */
unsigned int crypto_max_overhead(void);
void crypto_read_openvpn_key(const struct key_type *key_type,
struct key_ctx_bi *ctx, const char *key_file,
bool key_inline, const int key_direction,
- const char *key_name, const char *opt_name);
+ const char *key_name, const char *opt_name,
+ struct key2 *keydata);
/*
* Inline functions
*/
const char *print_key_filename(const char *str, bool is_inline);
+/**
+ * Creates and validates an instance of struct key_type with the provided
+ * algs.
+ *
+ * @param cipher the cipher algorithm to use (must be a string literal)
+ * @param md the digest algorithm to use (must be a string literal)
+ * @param optname the name of the option requiring the key_type object
+ *
+ * @return the initialized key_type instance
+ */
+static inline struct key_type
+create_kt(const char *cipher, const char *md, const char *optname)
+{
+ struct key_type kt;
+ kt.cipher = cipher;
+ kt.digest = md;
+
+ if (cipher_defined(kt.cipher) && !cipher_valid(kt.cipher))
+ {
+ msg(M_WARN, "ERROR: --%s requires %s support.", optname, kt.cipher);
+ return (struct key_type) { 0 };
+ }
+ if (md_defined(kt.digest) && !md_valid(kt.digest))
+ {
+ msg(M_WARN, "ERROR: --%s requires %s support.", optname, kt.digest);
+ return (struct key_type) { 0 };
+ }
+
+ return kt;
+}
+
+/**
+ * Checks if the current TLS library supports the TLS 1.0 PRF with MD5+SHA1
+ * that OpenVPN uses when TLS Keying Material Export is not available.
+ *
+ * @return true if supported, false otherwise.
+ */
+bool check_tls_prf_working(void);
+
#endif /* CRYPTO_H */
projects / thirdparty / openvpn.git / blobdiff